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Antioxidants, diet and
degenerative diseases
Paul R Earl
Facultad de Ciencias Biológicas
Universidad Autónoma de Nuevo León
San Nicolás, NL, Mexico
Do modern life styles reduce longevity ?
Our plan is to lead a long and happy life, yet how
this is to be done may not be clear for certain age
groups, life styles and special problems like
cultural disputes or lack of job skills. This plan
includes desirable weight, regular excercise and
abstinence from smoking, excessive alcohol and
elicit drug use. Diet education can be one of the
dominant themes. Especially beneficial foods are
soya, unsaturated fatty acids, phytosterols and
phytosterol esters, carotenoids, polyphenols,
phytoestrogens and flavanoids, etc., dietary fiber,
vitamins E, C and B, folic acid and selenium,
potassium, zinc and magnesium.
Will you last longer if you eat less ?
Obesity, diabetes mellitus, hypertension,
hyperlipidemia, coronary artery disease and
some cancers like breast cancer are
sometimes considered life style diseases.
The AIDS disaster, hunger and povery may not
allow a clear vision of the present universal
TRANSITION from focus from acute infectious
diseases to chronic ones.
Antioxidants are protective agents that inactivate
reactive oxygen ions and thus delay or prevent
oxidative damage. Antioxidant enzymes like
superoxide dismutase, catalase and glutathione
peroxidase are naturally present within human cells.
In addition, antioxidants such as vitamins E and C
(ascorbic acid), polyphenols and carotenoids are
available in food.
Current dietary guidelines to combat chronic
diseases, including cancer and coronary artery
disease (CAD), recommend increased intake of plant
foods. This includes fruits and vegetables, which are
rich sources of antioxidants. The role of dietary
antioxidants, including vitamin C, vitamin E,
carotenoids and polyphenols in disease prevention
is emphasized.
Flavanoids
Flavonols, flavones and isoflavones belong
to the 3 subclasses of flavonoids. Flavonols
and flavones have similar C-ring structure
with a double bond at the 2-3 position.
Flavones, as opposed to flavonols, lack a
hydroxyl group at the 3-position. Major
flavonols include quercetin (3,5,7,3’,4’pentahydroxyflavone), kaempferol (3,5,7,4’tetrahydroxyflav-one) and myricetin
(3,5,7,3’,4’,5’-hexahydroxyflavone).
Another important dietary antioxidant is
lycopene of tomatoes.
The most widely found compounds are
flavonols, flavones, flavan-3-ols,
isoflavones, flavanones, flavanols,
anthocyanidines and proantho-cyanidines.
Flavonoids are almost ubiquitous in plant
foods (vegetables, cereals, legumes, fruits,
nuts, etc.) and beverages (wine, cider, beer,
tea, cocoa, etc.). Treat potatoes as just
starch !
Sources of antioxidants
Allium sulphur
compounds:
leeks, onions and garlic.
Anthocyanins:
eggplant, grapes and berries.
Beta-carotene:
pumpkin, mangoes, apricots, carrots,
spinach and parsley.
Catechins:
red wine and tea.
Copper:
seafood, lean meat, milk and nuts.
Cryptoxanthins:
red capsicum, pumpkin and mangoes.
Flavonoids:
tea, green tea, citrus fruits, red wine,
onion and apples.
What is a serving ?
One medium-sized fruit or vegetable is the
simplest form of a serving. A serving can be
125 ml or 1/2 a cup of raw, cooked, frozen or
canned vegetables or fruit. A perfect
example is a small glass of orange, carrot or
tomato juice. Drinking juice made from
concentrate will not do. Instead, buy real
juice with pulp which includes all the
essential nutrients. The serving is a
convenient yet vague term, perhaps of
237-250 ml. A slice of bread is a serving.
Diet
1/ Choose a VARIETY of foods.
2/ Balance the food you eat with physical
activity. Maintain or improve your weight.
3/ Choose a diet with plenty of grain
products, vegetables and fruit.
4/ Choose a diet low in fat, saturated fat and
cholesterol.
5/ Get a diet moderate in sugars, salt and
sodium.
Lower
1,600
Moderate
Higher
2,200
2,800 calories
Grain Group Servings
6
9
11
Vegetable Group Servings
3
4
5
Milk Group Servings
2-31
2-31
2-31
Meat Group2 (ounces)
5
6
7
Total Fat3 (grams)
53
73
93
Total Added Sugars4 (teaspoons)
6
12
18
Fruit Group Servings
2
3
4
Recommended Antioxidant Good Food Sources.
Amount*
Vitamin C
Women: 75 mg of citrus fruits, cruciferous vegetables such
as broccoli, cauliflower and cabbage.
Men: 90 mg. Smokers: extra 35 mg.
Vitamin E
15 mg of fortified cereals, vegetable oils, nuts, spinach and
kale, mangoes and wheat germ.
Selenium
55 micrograms (mcg). Onions, garlic, mushrooms, wheat
germ and rice bran.
Vitamin A Women: 700 units as retinol: As beta-carotene:
RAE** Eggs, liver, yellow-orange or dark-green leafy
vegetables and fruits.
Men: 900 REA vitamin such as kale, beet greens, spinach,
carrots, sweet potatoes, A-fortified milk, pumpkin, papaya,
apricots, parsley and basil.
Down with fat !
Too much fat or cholesterol and inactivity
can make you fat. Change from
Whole or 2 % milk to 1 % skim milk.
Regular cheese to low-fat cheese.
Mayonnaise to mustard or low-fat
mayonnaise
Fried to baked chicken.
Saturated fat to olive oil. corn oil or canola
(rape seed extract).
Bologna, salami or pastrami to sliced turkey
or lean beef.
Some useful links
Antioxidant vitamin therapy
Nutrition and health (in Russian)
http://www.pitt.edu/~super1/lecture/lec10541/index.htm
Mediterranean diet and cardiovascular disease
prevention
http://www.pitt.edu/~super1/lecture/lec3261/index.htm
Lipids and cardiovascular disease prevention
http://www.pitt.edu/~super1/lecture/lec5261/index.htm
and
http://www.pitt.edu/~super1/lecture/lec5271/index.htm
Body Mass Index & Basal Metabolic Rate
Obesity is measured by the Body Mass Index
(BMI). The BMI was invented by the Belgian
mathematician Quetelet (1796-1874) who was
fortunate enough to be a student of both La Place
and Fourier. This universally applied index is
weight in kg over height in m squared.
BMI is one of the few factors (variables) that
applies equally to men and women.
Another measure is the Basal Metabolic Rate
(BMR). The basal metabolic rate is calculated in
kilocalories/day according to equations given by
Harris & Benedict in 1919. But see Weir, J Physiol
1949;109:1–9. Also it can be given as
kilojoules/min or kJ/day.
Cholesterol
When there is too much cholesterol in the
blood, it builds up in the walls of the arteries
to become atherosclerosis or hardening of
the arteries. When blood cannot circulate
normally, there may be chest pains and even
a heart attack.
These values are: Total cholesterol LDL (low
density bad ! cholesterol) – the main source
of cholesterol buildup and blockage in the
arteries, HDL (high density good !
cholesterol) – helps stop cholesterol from
building up in the arteries. Triglycerides are
another form of fat in blood.
The diseases
Obesity
The central issue might be lack of discipline to
control overeating, but this conclusion may be
wrong. Still, eating can be viewed as one more
addiction, and next our society makes this a
moral issue thus making it too easy to insult
fat people. Nevertheless, the food addict lives
in his own world and will have to break his
own chains.
Obesity has 30.0 or more BMI, whereas
overweight is 25.0-29.5 BMI. The normal range
is 18.5-24.9 BMI. Below 18.5 BMI is the
condition anorexia nerviosa in young women
who grievously undereat.
Diabetes
Insulin is not produced in Type 1 and not
properly used in Type 2 diabetes.
High carbohydrate, high fiber diets can
reduced insulin dosage by 40 %, fasting blood
glucose by 6-27 % and serum cholesterol by
10-32 %. See also Jenkins et al, N Engl J Med
1993: 329: 21-26.
Like obesity, diabetes is an extremely active
field that is expected to take great strides
now. Nonetheless, diabetes will kill those who
do not follow their diet.
Atherosclerosis
Atherosclerosis takes place in the major
arteries and is the underlying cause of heart
attacks, stroke and peripheral artery
disease. The earliest detectable lesions,
called fatty streaks, contain macrophage
foam cells that are derived from recruited
monocytes. More advanced lesions, called
fibro-fatty plaques, are the result of
continued monocyte recruitment and
smooth muscle cell migration and
proliferation.
Hypertension
One central theme is enough oxygen for normal
cardiac function.
Angina pectoris has chest pain arising from the
heart due to a lack of oxygen to the heart
muscle. It can be brought on by exercise,
emotional upset or heavy meals. Normally the
arteries that supply blood to the heart can cope
with an increased demand, but if coronary artery
disease (CAD) is present or high blood pressure,
the blood flow is restricted. CAD affects men
over age 35 and postmenopausal women.
Stroke
A stroke or "brain attack" occurs when a blood
clot blocks an artery or a blood vessel breaks,
interrupting blood flow to an area of the brain.
Brain cells begin to die, and damage occurs.
Abilities controlled by that area of the brain are
lost. These abilities include speech, movement
and memory. Some people recover completely
from strokes, but more than 2/3 of survivors will
have some type of disability.
The risk of having a stroke is perhaps 1 % per
year. Reduce cholesterol. Try an aspirin a day,
but this is surely not for everyone.
Macular degeneration of the retina
Macular degeneration damages and
destroys the central vision of up to one in 3
persons in their lifetime and has no known
cause or cure. It can affect anyone,
regardless of age or sex.
See http://www.eyesight.org/
Cancer
More fruit less meat and other advice for
general dietary improvement are simply
repeated for cancer prevention. Decisive
facts seem illusive.
More mutations thanks to exposure of DNA
to more free radicals can lead to various
cancers. Still, if “Just give us the facts” is
applied, little might be forthcoming.
Conclusions
The replacement of animal by plant proteins
has been repeatedly suggested. It seems
obvious that the heavily advertized foods
are the high calorie ones. These tasty highenergy foods are the ones to avoid! More
fruits, vegetables and fiber in the diet can
combat the obesity epidemic. As the
development of chronic lifestyle diseases are
strongly influenced by diet, and as we
CONTROL our diets, the timely dissemination
of nutritional knowledge seems imperative.
Up with soy and down with fried chicken!
Otherwise, just blame the genes.